The authority’s GCSE performance is among the lowest in Wales and many of its secondary schools are not reaching expected levels.

Fixed-term exclusions of five days or less are increasing and attendance in the primary sector is below the Welsh average across all measures.

But there is cause for optimism, with the borough’s capacity to improve considered “adequate” amid a culture of strong leadership.

Estyn commended Torfaen councillors for giving education a high priority and said strategic managers were aware of the areas requiring improvement.

Labour-led Torfaen was the 10th local authority in Wales to be judged under Estyn’s new inspection framework.

In their evaluations, inspectors rate on a four point scale of excellent, good, adequate or unsatisfactory for three key questions.

So far in Wales, four councils have been considered adequate, three are good and three are considered unsatisfactory. There has been no excellent.

Mr Thomas, AM for Mid and West Wales, said: “Estyn’s report is damning and is further evidence that the current system is failing too many children in Torfaen, and across Wales.

“It is clear that root and branch reform is necessary. Our children are being let down by a system that is simply not good enough and this cannot be allowed to continue.”

Both the Welsh Government and Estyn’s chief inspector Ann Keane have recently criticised local authorities and their hold over school standards.

Next page: Report

In her annual report, Ms Keane said some councils do not track the progress of learners well enough and some schools had been allowed to under-perform for long periods.

Meanwhile, the Labour-led Welsh Government said it was not unreasonable to expect to see “excellent” local authorities in Wales.

Lynne Neagle, Labour AM for Torfaen, said there could be no excuses for the failings highlighted by Estyn.

“This is clearly an incredibly challenging and worrying report – it’s now absolutely incumbent on the local education authority to take on board and urgently act upon the comments and advice provided,” she said.

“There are simply no excuses for the kind of failings highlighted in this report. It also helps underline the fact that the Welsh Government was right to place a renewed and unrelenting focus on standards in our schools. Especially in these tough economic times, we simply have to ensure that we are delivering a first-class education to our young people and helping them to reach their full potential.”

Councillor Mary Barnett, Torfaen’s executive member for children and young people, said the authority accepted Estyn’s findings.

She added: “At the core of Estyn’s concerns is the performance of our secondary schools and our current standards of achievement particularly at Key Stage 4 [GCSE].

“As well as being more rigorous in supporting and challenging our secondary schools to raise standards, we recognise the need to bring all partners closer together in securing better outcomes for children and young people.

“Estyn recognise we have already implemented many new strategies to help tackle the issues and have demonstrated we are challenging whole-service performance. However, these have had too little time to demonstrate measured impact.”

Coun Barnett said Torfaen is supporting and challenging its secondary schools on “an unprecedented level” – and it expects to see standards improve in the summer.

A spokesman for the Welsh Government said Education Minister Leighton Andrews was “disappointed” by Estyn’s report on Torfaen.

“The local authority must now produce an action plan within 50 working days of receipt of the report setting out how it will respond to Estyn’s recommendations,” he said.

“The minister will review the situation based on Estyn’s advice on the robustness of that action plan. The authority will be subject to follow up activity in the form of Estyn monitoring.”

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